Ok, I've asked enough questions on this forum already the past few months. Time for me to provide some hopefully useful info. This is kind of a long post, but to get to the point, I looked at various fert dispensers and came up with some recommendation.
I'm just starting my fert dosing. I wasn't too sure what to do about the daily dispensing of ferts plus Excel. I knew I didn't want to do dry dosing. It just seemed like too much extra daily work. So the question was what dispensers to use for liquid dosing. I have the follow planted tanks:
10g low light (finally planted today)
6g med light (will plant tomorrow)
46g med-high light (will plant tomorrow)
Because of this, I'd need two sizes of dispensers, since one size would not work for all tanks, but the same should work for the two smaller tanks. The first dispenser my research turned up was the one at Green Leaf Aquariums
This could work for the 46g, but $6 x 3 plus shipping just seemed like too much to pay, plus it did not provide the smaller dispenser size I needed for the small tanks. I bit more research on PT turned up a couple of sites that sell various dispenser bottles:
They each had ones I though would work with at least one tank. Basically all bottles are about $1, so I ordered enough of the ones I thought would work best, plus a few "samples" of others just in case they worked out better. Here are the bottles I ordered:
Amber PET Cosmo Plastic Bottle 8oz w/ Black Pump
Amber Boston Round Glass Bottle 4 oz w/ Blk Pump
Amber Boston Round Glass Bottle 4 oz w/ Dropper
Amber Boston Round Glass Bottle 2 oz w/ Dropper
16 oz. Bottle 1/2 and 1 oz Dispensing Chambers 28/410 Neck
8 oz. Bottle 1/4 and 1/2 oz. Dispensing Chambers 24/410 Neck
8oz Translucent Bottle and Pump 28mm Cap
16oz Translucent Bottle and Pump 28mm Cap
#1, #2, #7, and #8 are all pump/squirt type models which dispense about 1ml per squirt. While convenient, I saw two problems. The first is the cap leaks when you shake the bottle. The 2nd is that I'm assuming the first squirt each morning will often be less than 1ml due to temp and pressure changes. This makes it unpredictable how much will be dispensed. I never actually tested this theory, since the leaking cap was enough to make me realize not to even bother.
#3 and #4 are similar. The are both quality amber glass bottles with glass droppers that reach the bottom. #3 (4oz) dispenses about .9ml and #4 (2oz) dispenses about .7ml. I like these bottles and these are the ones I chose to use for my smaller tanks.
#5 and #6 are like the Green Leaf Aquarium dispensers (at 1/4 the price). There is also a larger 32oz. I also like these and they are what I use for the 46g. Note when choosing a size, keep in mind that it is hard to dispense less than 1/2 what the dispensing chamber holds. The 8oz (which I use) has a 1/2 oz dispensing chamber and also has a mark at 1/4 oz. This means you'll get a total of 32 dispenses if you choose the smaller 1/4 oz amount to dispense. I would not recommend trying to dispense less than the smaller amount, since you won't be able to do so accurately. Thus to maximize the number of dispenses you get from the bottle, while still dispensing an accurate amount, choose a bottle size whose smaller dispensing amount is the amount you want to dispense.
That's about it. Hope you find this useful.